'80 GS450 twin, electrical issues

[Guest]

Ok I'm only half awake and this is probably a repeat of some of apoplectic's stuff, but I'll stick it here anyway:

The thinner ground wires from the battery should go to the frame and the electrics plate.

The thick ground wire should go to the engine and should be terminated under one of the crank case bolts (this is to cope with the return current from the starter motor).

(If I was you I would do some modification to the electrics plate to make sure everything possible grounds to the same grounding point as the wire that goes back to battery negative)

The thick positive wire should go to one terminal on the starter solenoid.

The thin positive wire should go to the inline fuse.

The other end of the inline fuse should go to a red wire with a female bullet connector that comes out of the harness at about the same point as the yellow/green starter solenoid trigger wire.

The reason your indicators won't be working could be either not enough voltage or a bad ground or both. I had both issues on mine when I first hooked them up.

The horn could be simply that it's had enough. There is a thread or an article somewhere around on how you can repair them.

[Trevor76]

Okay, some more progress tonight:

All battery wires are now wired in EXACTLY as Pete has described above.
On the electrics plate the R/R, Ignitor, and main harness are all grounded to a single point, where the new wire I added tonight is in turn grounded and leads back to the battery negative.

As I write this I realize that the solenoid isn't grounded to anything, other than through the connection to the electrics plate itself...

I made a new positive battery lead with 10GA wire for the main line and 12GA branching off to meet the fuse. These two wires are crimped together with a battery terminal connector so that the whole thing closely resembles the stock setup (with the exception of the blade fuse in place of the glass fuse of course).

Turn signals are flashing now, albeit weakly. I replaced the stocker with one that I've had laying around for a few years. Also I cut the connection off of the wiring harness and spliced in the connection from the original harness -it just looked to be in better shape.


The flashers won't work when I turn the high beam on so Pete's "not enough voltage or a bad ground or both" theory sounds spot on.

Still no lights behind the tach or speedo, but the turn signal indicator, HI/LO, neutral and oil warning are all lit...(why was the oil light lit?)
This may be another indicator of low voltage as I assume that it takes more power to light the tach and speedo than the dummy lights...or maybe the bulbs are just burnt out.

Also I pushed the bike through all of the gears and the corresponding lights all worked.

Horn still is not working, I think it has simply given up the ghost and am not suspecting the wiring at this point...assuming that it is the horn itself then that means that all left-hand control are wired in and working properly except for the light switch, which for some reason is stuck in the "on" position.

Still no magic when I push the Start button, so I need to remove the right-hand control housing. Last time I tried to do that I stopped because I found that the mounting bolts were completely stripped. I ended up just grafting on the connector from the replacement control that I bought, as that one looked really awful and sun faded anyhow.

The solenoid is working, remember it is that brand new one from Rick's. I accidentally crossed both posts and in effect "jump started" the bike, giving myself a fright in the process...

And all of this experimentation began with a fully carged battery reading 12.something volts.

So, the issues seem to be low voltage, possibly still a bad ground (do I need to ground that solenoid better???), or maybe a
bad wire/connection within the right-hand control box.

I decided to leave the battery in overnight, and to check its state of charge tomorrow night. I figure it it goes dead in 24 hours then that's a sure sign of a bad ground/slow drain...right?

Any other theories?

Thanks guys, I think I'm almost there

[apopleptic]

12.something is pretty vague. I think less than 12.5 is no good. Are you sure the battery has a good charge? and did you ground to the engine and harness as well? or just the electrical plate and frame? I am having a heck of a time getting a picture of where my engine ground is but if I have time tomorrow I'' try to get a picture from underneath.

[Guest]

Ok, that definitely sounds like you're making good headway!!!

So at this point the main grounds should be covered off as long as where you've attached them isn't a painted surface and isn't corroded or anything like that.

The starter solenoid's body is the ground on the stock solenoid, so it's probably the same with your replacement one. That leads me to think that maybe those mounting points are painted and it's not grounding properly?

As for your gauge backlights not lighting up, that could simply be blown bulbs in there, I replaced mine with LED's due to having an intermittent issue at one point.

To test your horn wires, simply put a multimeter across the two terminals and hit the horn button, should show 12v while holding the button down.

Your oil light absolutely should be on when the ignition is on and the engine is off. It's actually an oil pressure (or lack thereof) indicator, so it will turn off once the oil pump has pressurised the oil system with the engine running.

There's possibly still an issue in your right controls, so I'd say pull it apart and clean time...

[Trevor76]

Can't remember offhand but I think it was like 12.62 or something? In any event the battery tender was showing a green light as was the LED on my multimeter's battery check feature.

I know, an actual number would be more scientific I just can't remember what it was reading but I will check the battery again when I work on it tonight or tomorrow.

If the gauge lights are indeed burnt out then I will most likely go the LED route, if I remember correctly there is a tutorial for that somewhere on Basscliff's site or maybe it was a topic here on GSR...

If I'm not mistaken they draw less voltage anyhow.

So next steps are to use either a small cutoff wheel or bolt extractor to get that R/H housing off and to see what's going on in there, and while I have the Dremel out I may as well throw a sanding attachment on there and buff the hell out of every ground point.

A quick question to clarify the procedure for checking the horn -am I setting the multimeter to the continuity (ohms) setting, or is it DC voltage? And does the battery need to be attached or detached?

Sorry for such rudimentary questions, still learning my way around a multimeter and the black art of electricity...

The upside of all of this poking and probing is that I am becoming intimately familiar with every inch of wiring on the bike.

[Trevor76]

Oh, that's funny! "Gauge LED modification thread"...is in Pete's signiture.
I knew I had seen that somewhere

[Guest]

Hahaha mate it's all good, I've gone searching many a time only to see the thread or link right in front of me...

But the original gauge LED modification was by Matchless and is on BassCliff's site...

To measure the horn, you want DC volts and you'll need the battery in and I think the ignition and kill switches may need to be on also, can't remember if you can hit the horn with them off or not...

[Trevor76]

I have tracked the issue down to the right hand control box.

Last night after work I stuck the key in to see if the battery still had enough juice to run the lights, etc.

It did, and for kicks I tried the starter button -it worked! The problem seems to be a poor connection somewhere within the housing, and when I had moved the wires around the other night it must've made the connection.
The problem is not fixed, I still have to pull the housing off when I get a chance to mess with that stripped bolt. But at least the issue has been identified.

While I had the solenoid firing I went ahead and stuck the tank back on and connected the fuel feed, thinking I would give it a go and see if I could get the bike running.

I set the petcock to "prime", and saw fuel trickling through the fuel filter but no combustion.
Used the choke but to no avail. And the strange part is that there was a smell very similar to rotten eggs coming from somewhere...that's a first for me, I'm guessing that it may be bad gasoline? I had drained the float bowls of the carbs when I removed the tank last month so there shouldn't be any old fuel in there, maybe the gas in the tank is bad?

Of course there may be issues within the ignition system, as I have replaced the signal generator, ignitor, and coils...and while I'm convinced that they are all wired in correctly that doesn't mean that all of this stuff actually works!

[Guest]

I have tracked the issue down to the right hand control box.

Last night after work I stuck the key in to see if the battery still had enough juice to run the lights, etc.

It did, and for kicks I tried the starter button -it worked! The problem seems to be a poor connection somewhere within the housing, and when I had moved the wires around the other night it must've made the connection.
The problem is not fixed, I still have to pull the housing off when I get a chance to mess with that stripped bolt. But at least the issue has been identified.

While I had the solenoid firing I went ahead and stuck the tank back on and connected the fuel feed, thinking I would give it a go and see if I could get the bike running.

I set the petcock to "prime", and saw fuel trickling through the fuel filter but no combustion.
Used the choke but to no avail. And the strange part is that there was a smell very similar to rotten eggs coming from somewhere...that's a first for me, I'm guessing that it may be bad gasoline? I had drained the float bowls of the carbs when I removed the tank last month so there shouldn't be any old fuel in there, maybe the gas in the tank is bad?

Of course there may be issues within the ignition system, as I have replaced the signal generator, ignitor, and coils...and while I'm convinced that they are all wired in correctly that doesn't mean that all of this stuff actually works!

Cool! Good to hear you got some action

While you've got it apart, spray contact cleaner on everything.

The starter button contacts on mine were black and cleaned right up, same with the contact areas for the kill switch.

You'll need to test for spark properly too, and don't forget if your floats are dry it will take a bit before it'll suck in enough fuel to kick over.

Not sure on the rotten egg smell but if that fuel's been in the tank for any more than a couple of months I'd probably turf it just to be sure...

[Trevor76]

So I had to detour for a few days, dug up an old thread on starter motors and it seems mine is a goner. Weird, because the starter worked when I brought this thing home.

Maybe I burned it up trying to start the bike over and over.

So I bid on one on Ebay, and won. $35 plus shipping, for one that seems to be in very good condition. A nice price but man costs are REALLY getting out of hand on this project. So today I put together a list of all of the stuff I have removed from the bike and put an ad in the for sale section, hopefully I can get a little back.

In other news I pulled the gauge cluster off and sure enough the bulbs behind the gauges are burnt out. So I will go to Autozone or NAPA to find replacements, and may go the LED route.

I was finally able to work the rightside control housing free and cleaned the contacts as best as I could with contact cleaner and a little wire brush. Lots of funk and cobwebs in there, much better now.

Also, I replaced the headlight lamp with a Xenon 60/55w bulb, as I had an extra one that was originally on the Honda.

As for that rotten egg smell, another member commented that batteries often smell that way RIGHT BEFORE EXPLODING...that has me a bit freaked out, and I'm hoping that with a new starter motor in there that I will never smell that smell again.

Otherwise...I may be in the market for a new battery, and if that's the case then this project gets shelved until springtime.

[Guest]

So I had to detour for a few days, dug up an old thread on starter motors and it seems mine is a goner. Weird, because the starter worked when I brought this thing home.

Maybe I burned it up trying to start the bike over and over.

So I bid on one on Ebay, and won. $35 plus shipping, for one that seems to be in very good condition. A nice price but man costs are REALLY getting out of hand on this project. So today I put together a list of all of the stuff I have removed from the bike and put an ad in the for sale section, hopefully I can get a little back.

In other news I pulled the gauge cluster off and sure enough the bulbs behind the gauges are burnt out. So I will go to Autozone or NAPA to find replacements, and may go the LED route.

I was finally able to work the rightside control housing free and cleaned the contacts as best as I could with contact cleaner and a little wire brush. Lots of funk and cobwebs in there, much better now.

Also, I replaced the headlight lamp with a Xenon 60/55w bulb, as I had an extra one that was originally on the Honda.

As for that rotten egg smell, another member commented that batteries often smell that way RIGHT BEFORE EXPLODING...that has me a bit freaked out, and I'm hoping that with a new starter motor in there that I will never smell that smell again.

Otherwise...I may be in the market for a new battery, and if that's the case then this project gets shelved until springtime.

If the starter motor's playing up you can usually dismantle and clean up the insides. Pretty sure you can file/clean up the brushes or replace them which is usually the first thing to go I believe. However $35 for a used one in good condition is a good price

I hear ya' on the costs though, every time I turn around there's another little think I need to buy, and it certainly does add up.

I'm ignoring that now though because mine *has* to go on the road this year! Dying to ride...

[Trevor76]

So, I am off of work tonight and tomorrow and hope to get back to the bike.

To sum things up, the new starter motor arrived very quickly, and is indeed in very nice shape. The seller claims that the bike it came from had less than 700 miles before being converted to a track bike.

Last night I removed all of the hardware keeping the airbox in place and loosened the clamps around the carbs, but didn't have adequate lighting to go much further.

So the plan tonight is to finish the carburetor and cam chain tensioner removal so that I can get the new starter motor in.

I will check out the carbs and tensioner while I have them off.

Also, I will triple-check all of the cables relating to the battery, solenoid and starter motor. When I spoke with an engineer friend of my brother, he said that the "rotten egg" smell that I have been experiencing is most likely due to something being shorted to ground. According to him the sulfur-like smell accompanies a battery that is unloading large amounts of charge very quickly -such as a when there is a major short to the frame. So, if that is what is happening maybe I can track it down.

Also I have a package of NOS gauge bulbs coming in to replace the tach/speedo lights. I am refraining from an LED upgrade at this time but that may happen in the future.

[Guest]

So, I am off of work tonight and tomorrow and hope to get back to the bike.

To sum things up, the new starter motor arrived very quickly, and is indeed in very nice shape. The seller claims that the bike it came from had less than 700 miles before being converted to a track bike.

Last night I removed all of the hardware keeping the airbox in place and loosened the clamps around the carbs, but didn't have adequate lighting to go much further.

So the plan tonight is to finish the carburetor and cam chain tensioner removal so that I can get the new starter motor in.

I will check out the carbs and tensioner while I have them off.

Also, I will triple-check all of the cables relating to the battery, solenoid and starter motor. When I spoke with an engineer friend of my brother, he said that the "rotten egg" smell that I have been experiencing is most likely due to something being shorted to ground. According to him the sulfur-like smell accompanies a battery that is unloading large amounts of charge very quickly -such as a when there is a major short to the frame. So, if that is what is happening maybe I can track it down.

Also I have a package of NOS gauge bulbs coming in to replace the tach/speedo lights. I am refraining from an LED upgrade at this time but that may happen in the future.

Cool, glad to see you getting back into it, looking forward to seeing what you find

[Trevor76]

Not much luck tonight. I pulled the original starter motor and tested it with the battery, it seems to work just fine. I replaced it with the new one anyhow but now I have two functioning starter motors, one for sale.

Camchain tensioner and carbs all looked pretty clean, so they will go back on tomorrow.

All of the battery cables looked good upon inspection. The ground wire that goes from battery(-) to the engine casing looked fine but I couldn't tell if it was making good contact at its mounting point, which is a engine bolt. the bolt itself was rusty and corroded so I thought that my problem might be there. Anyone familiar with that bolt/ground point can attest to how much of a pain it is to get a wrench in there -there was no way a socket was going to fit. After about 45 minutes i decided to hell with it and cut the wire, connected a new ring terminal and mounted it on the next bolt down (closer to the bottom of the case, by the center stand).
I used a stainless steel washer to make sure there was a good ground, and checked continuity with a multimeter. Should be good to go.

All of this to no avail.
I'm still not getting the starter motor to turn over with the starter button.
Clutch safety switch is bypassed. Kill switch is "ON"...
Battery charged. The most that I am getting from either starter motor is a sort of "click" when I run a wire directly from the battery (+) to the starter's terminal.

When the starter was off of the bike I hooked it up to the battery by running a ground wire from the motor mount to (-) and a wire from (+) to the terminal. The motor turns, but not quite as powerfully as I would have expected. This is true for both of the motors I have. Again this is with a battery that is close to a full charge.

So, starter motor(s) are good, wiring all seems to be in good shape...is it the battery?

[Guest]

Not much luck tonight. I pulled the original starter motor and tested it with the battery, it seems to work just fine. I replaced it with the new one anyhow but now I have two functioning starter motors, one for sale.

Camchain tensioner and carbs all looked pretty clean, so they will go back on tomorrow.

All of the battery cables looked good upon inspection. The ground wire that goes from battery(-) to the engine casing looked fine but I couldn't tell if it was making good contact at its mounting point, which is a engine bolt. the bolt itself was rusty and corroded so I thought that my problem might be there. Anyone familiar with that bolt/ground point can attest to how much of a pain it is to get a wrench in there -there was no way a socket was going to fit. After about 45 minutes i decided to hell with it and cut the wire, connected a new ring terminal and mounted it on the next bolt down (closer to the bottom of the case, by the center stand).
I used a stainless steel washer to make sure there was a good ground, and checked continuity with a multimeter. Should be good to go.

All of this to no avail.
I'm still not getting the starter motor to turn over with the starter button.
Clutch safety switch is bypassed. Kill switch is "ON"...
Battery charged. The most that I am getting from either starter motor is a sort of "click" when I run a wire directly from the battery (+) to the starter's terminal.

When the starter was off of the bike I hooked it up to the battery by running a ground wire from the motor mount to (-) and a wire from (+) to the terminal. The motor turns, but not quite as powerfully as I would have expected. This is true for both of the motors I have. Again this is with a battery that is close to a full charge.

So, starter motor(s) are good, wiring all seems to be in good shape...is it the battery?

If you're unsure of your battery, then I'd suggest trying with one you know is good.

So far, all my testing has been done with one of the car's batteries as I haven't got one for the bike yet specifically because I need a bit more of a grunty one while testing things.